[Haskell-cafe] Needed: A repeatable process for installing GHC on Windows

[Claus Reinke]

>>> Earlier today I was trying to set up a Windows build bot for the
>>> 'network' package. That turned out to be quite difficult. Too much
>>> playing with PATHs, different gcc versions, etc. Does anyone have a
>>> repeatable, step-by-step process to install GHC and get a build
>>> environment (where I could build network) going?

If you don't need to build GHC yourself, then the binary installers
(or daily snapshot builds) should come with their own copy of GCC 
tools. So you only need some shell/autoconf environment on top
(either cygwin or MSYS). Fewer things to go wrong than in the past,
but cygwin's configure scripts tend to think they're on unix, and
for MSYS, it can be difficult to get the right pieces together.

Snapshots should appear as installers and tar-balls here:

    http://www.haskell.org/ghc/download#snapshots

but windows build failures tend to go unnoticed for a while,
so you might have to send a heads-up to cvs-ghc at .. if you 
need up to date builds.
 
> No, but I used to (and sadly can't find it any more). I used to have a
> script called ghcsetup which built GHC on Windows, and importantly
> validated the setup was correct (the right gcc was first in the path
> etc) and took actions to correct it.
> 
> I am sure there used to be a great web page on the GHC wiki, saying
> the exact steps to build (written by Claus), but I can't find it any
> more. Perhaps Claus knows where it has gone?

Yes, I ran into this so often that I made a record of the "build
your own GHC" steps one time, together with a cygwin package
description that recorded the cygwin packages needed for such
builds. Both cygwin and GHC have moved since then, and I guess
someone decided it was too much trouble to keep the step-by-step
guide up to date, or perhaps it was no longer needed (check with 
GHC HQ to be sure)?

If you do need to build your own GHC head, the GHC wiki building 
guide has a page on 

    "Setting up a Windows system for building GHC"
    http://hackage.haskell.org/trac/ghc/wiki/Building/Preparation/Windows

which not only claims to list suitable MSYS versions, but holds
copies (so you don't have to hunt for the MSYS packages), as well
as links to other necessary tools (python, alex, happy, darcs). What
I do not know is whether the versions are still up to date (check
with GHC HQ).

As usual, if the wiki page instructions are not working anymore,
please add a note, and include any improvements you figure out;-)

Claus

PS. GHC no longer uses buildbot, it has its own builder, so if
    you really want to set up a build bot, you can probably copy
    GHC HQ's setup for the purpose?